The present invention relates to beds and, more particularly, to adjustable, multiple position care beds.
Adjustable beds are commonly used in the healthcare field, including the institutional and home healthcare markets. Typical adjustable beds include a mattress frame or mattress support which is divided into a plurality of sections, including a head section, a seat section and a leg or foot section. These sections are pivotally interconnected and have a continuous range of adjustment. The sections are movable from a flat, patient resting position to a seated position with the legs bent or the legs straight and the patient's back angled upwardly with respect to a seat section. The sections are pivoted by motor drives, hand-operated cranks or through the patient's weight.
Full electric beds currently available typically include three electric motors to achieve the various adjustments. One motor operates the head section for back articulation. A second motor articulates the leg and knee sections to place them in a knee break position. A third electric motor operates the high/low mechanism which raises and lowers the mattress frame. The mattress frame or surface is typically lowered for sleeping but moved to a high position when patient care is being given. Raising the surface reduces back strain while changing dressings, bandages, clothing and while performing other like operations.
Examples of multi-position, adjustable beds may be found in commonly owned U.S. Pat. No. 5,245,718 entitled ADJUSTABLE BED WITH SINGLE ACTUATOR, which issued on Sep. 21, 1993, to Krauska; commonly owned U.S. Pat. No. 5,105,486 entitled ADJUSTABLE BED, which issued on Apr. 21, 1992, to Peterson; U.S. Pat. No. 3,246,540 entitled SIX-WAY DRIVE UNIT, which issued on Apr. 19, 1966, to Pickles et al. and U.S. Pat. No. 3,132,351 entitled HOSPITAL BED, which issued on May 12, 1964, to Huntress et al.
The Krauska patent discloses a bed which includes a single electric motor drive or actuator to operate a high/low mechanism and to adjust the mattress frame sections to position the user in a seated or back raised position. The actuator functions to articulate the mattress sections only when the mattress frame is in a fully lowered position.
The Peterson patent discloses a bed which includes multiple mattress frame sections and link and positioner subassemblies. A separate high/low mechanism is provided for raising the mattress frame. The frame sections may be articulated with respect to each other when the mattress frame is in a high or in a low position.
Examples of other adjustable beds may be found in U.S. Pat. No. 3,036,314 entitled ADJUSTABLE BED, which issued on May 29, 1962, to Wetzler and U.S. Pat. No. 4,472,846 entitled COUPLING SYSTEM FOR THE MOTOR DRIVE IN AN ADJUSTABLE MOTORIZED HOSPITAL BED, which issued on Sep. 25, 1984, to Volk, Jr., et al. The Wetzler patent discloses an adjustable bed including a high/low mechanism and a single drive motor. In Volk, Jr., et al., an adjustable bed is disclosed wherein different adjustment functions including high/low, back and knee adjustments are made by a single, reversible motor which is selectively coupled to a plurality of output drive shafts by a multiple clutch arrangement.
Beds heretofore provided which achieve all desired adjustment functions with motorized actuators have tended to be costly and complex. Prior approaches which have provided a single electric drive to perform all functions have suffered from undue complexity and operational difficulties. In the typical institutional or home-care market, the customer may desire full adjustability but may not be willing to pay for an adjustable bed having three drive actuators. The customer may only be able to afford a semi-electric bed which includes a pair of electric drives for head and knee positioning and a manually cranked, high/low mechanism. Beds with an electric high/low mechanism are safer for use by the caregiver. Such beds reduce back strain which may be occasioned by bending and cranking to raise the bed. Full electric beds which include three electric actuators are heavy. Typically, such beds may be delivered and installed in a home, for example, by a single delivery person. The individual may experience set up difficulties and may suffer back strain.
A need exists for an adjustable or articulated bed of reduced complexity from that heretofore provided and which is capable of achieving the full range of adjustment and movement between high and low positions with electric drives but at significantly reduced cost and weight from that heretofore available.